System for magnetic resonance and x-ray imaging

ABSTRACT

A patient table for a common imaging system including Magnetic Resonance and X-Ray retains the patient stationary in position prior to, during and subsequent to the imaging and includes a base, a patient support portion cantilevered from the base and a mattress. A safety system is provided for controlling the operation of the magnet and MR system and the X-Ray systems to allow effective safe operation and controls the movement of the magnet to the table and the movement of the X-Ray imaging systems to and from the table to locations where they do not interfere with the MR imaging.

This application claims the benefit under 35 U.S.C. 119 of ProvisionalApplication No. 61/058,657 filed Jun. 4, 2008, the disclosure of whichis incorporated herein by reference.

This application is a continuation-in-part of application Ser. No.12/333,032 filed 11 Dec. 2008.

This invention relates to system for use in magnetic resonance and X-Rayimaging of a patient.

BACKGROUND OF THE INVENTION

With MRI, a high field magnet, typically superconducting, is arranged ina torus configuration (like a donut) and with the patient lying downinside the magnet on a table where the magnetic field allows a pulsedand sequenced magnetic and EM field to probe the body to produce images,which allow the trained radiologist to determine with high probabilitythe anatomy of the patient. MRI is sometimes performed using contrastagents introduced to the patient to provide even better contrast betweendifferent tissue types. MRI techniques are very good at detecting theanatomical location of different diseases, for example, tumours,

In U.S. Pat. No. 5,735,278 (Hoult et al) issued Apr. 7, 1998, discloseda medical procedure where a magnet is movable relative to a patient andrelative to other components of the system. The moving magnet systemallows intra-operative MRI imaging to occur more easily in neurosurgerypatients, and has additional applications for liver, breast, spine andcardiac surgery patients.

In Published PCT Application WO07147233A1 of the present Applicantspublished Dec. 27, 2007 and entitled ROTATABLE INTEGRATED SCANNER FORDIAGNOSTIC AND SURGICAL IMAGING APPLICATIONS is disclosed an improvementto the above patent in which an additional rotational movement of themagnet is allowed.

A scanning system is known in which the patient is moved from an X-Rayimaging system to an MR imaging system by transferring the patient fromone imaging system to the other, for example, on a moveable table. TheMR scanner is used to provide information complementary to that obtainedusing X-Ray. It can be used, for example, to perform a baselineassessment prior to intervention as well as to perform apost-intervention assessment. Such an assessment may include perfusionand viability studies of the heart or of the brain.

U.S. Pat. No. 5,713,357 (Meulenbrugge) issued Feb. 3, 1998 and relatedU.S. Pat. No. 5,807,254 both of Phillips shows a combination of an X-Raysystem and an MRI system. The system is not for intra-operative uses andthe magnet is not a cylinder. The magnet is not moved. The X-Ray ismoved side to side in FIG. 2. The patient is moved in FIG. 1.

U.S. Pat. No. 6,101,239 (Kawasaki) issued Aug. 8, 2000 to Hitachiprovides an X-Ray and MRI operating simultaneously at the same locationand methods to operate them in a timed manner to avoid interference.However this arrangement is not suitable for interventions by themedical team since the presence of the machines restricts access to thepatient.

U.S. Pat. No. 6,385,480 (Bachus) issued May 7, 2002 of Siemens discloseswhat they call an angio-MR system where the radiographic angio-systemcooperates with the MR system. There is provided a moving patient tablewhich transfers the patient from the X-Ray system at one location to theMRI at a second location.

U.S. Patent Application 2006/0239524 (Desh) published Oct. 26, 2006 ofSiemens relates to diagnosis and treatment of cardiac diseases using MRIand X-Ray. This is directed to a method of combining the images toanalyze the diagnosis.

U.S. Pat. No. 6,975,895 (Pelc) issued Dec. 13, 2005 to Leland StanfordUniversity provides a modified X-Ray tube for use in magnetic fields ofan MRI system.

U.S. Pat. No. 6,658,085 (Sklebitz) issued Dec. 2, 2003 of Siemensdiscloses a system in which current for the coils generating themagnetic field of the MRI is calculated to reduce stray fields in thearea of the X-Ray system.

U.S. Pat. No. 5,865,780 (Tuite) issued Feb. 2, 1999 of SDGI Holdingsdiscloses a device for engaging and holding the body of the patientduring procedures in MRI and X-Ray imaging.

U.S. Pat. No. 6,812,700 (Fahrig) issued Nov. 2, 2004 of Leland StanfordUniversity discloses a related system in which the perturbations in themagnetic field of the MRI caused by the X-Ray system are compensated.

U.S. Pat. No. 4,595,899 (Smith) issued Jun. 17, 1986 to Leland StanfordUniversity provides an MRI system.

U.S. Pat. No. 5,099,846 (Hardy) issued Mar. 31, 1992 relates tocombining images from different imaging modalities and is primarilyabout the software for combining the images such as X-Ray and NMR.

U.S. Pat. No. 6,754,519 (Hefetz) issued Jun. 22, 2004 to Elgemsdiscloses two imaging systems such as CT and MRI where the two systemsare mounted on a common rail system for rolling movement from a commonposition to a spaced position.

U.S. Pat. No. 5,291,890 (Cline) issued Mar. 8, 1994 to GE discloses apatient heat treatment system where the heat is detected using an MRI.

U.S. Pat. No. 6,961,606 (DeSilits) issued Nov. 1, 2005 to Phillipsdiscloses two imaging systems such as CT and PET where the two systemsare mounted on a common rail system for rolling movement from a commonposition together for common scanning of the patient to a spaced apartposition.

German patent application 39 31 854 of Muller published Apr. 4, 1991discloses an NMR apparatus using a laser coagulation stereotacticsystem.

Japanese application 05344964 of Toshiba shows a combination of an X-Raysystem and an MRI system. This is application is filed only in Japan andprovides what is apparently a crude system.

Japanese patent application 4183446 published Jun. 30, 1992 by Res DevCorp of Japan discloses the use of MRI and X-Ray in a common apparatus.

One element which must be designed for use with a combined imagingsystem of the type described above is that of the patient support table.

SUMMARY OF THE INVENTION

It is one object of the present invention to provide an improved systemfor MR and X-Ray imaging using a patient table where the patient remainson the same table during both imaging steps.

According to a first aspect of the invention there is provided anapparatus for imaging of a part of a patient comprising:

a patient support table, the patient support table comprising;

a table support base for mounting in fixed position in an imaging suite;

and an upper patient support portion on which the patient can lie withthe part of the patient exposed for imaging;

the upper patient support portion being mounted for controlled movementthereof relative to the table support base;

a magnetic resonance imaging system for obtaining images of the part ofthe patient, the magnetic resonance imaging system comprising;

a magnet for use with a control system for controlling and varying themagnetic fields,

a radio frequency transmission and detection system for eliciting anddetecting from the part of the patient nuclear magnetic resonancesignals, in response to the magnetic fields, including RF coils arrangedto be located adjacent to the part of the patient;

and a computer and display monitor for decoding and displaying an imageobtained from the detected signals;

the magnet defining a coil surrounding a horizontal axis and defining acylindrical bore extending between axial ends of the coil of the magnetwith an imaging zone part way along the bore between the ends;

wherein the magnet is mounted on a magnet support arranged so that themagnet is movable longitudinally along its axis between a magneticresonance imaging position in which the magnet bore surrounds thepatient support portion while the patient support portion remainssupported on the table support base and a remote position in which themagnet is removed from the upper patient support portion by a distancesuch that the upper patient support portion is out of the strongmagnetic field of the magnet;

and an X-Ray imaging system comprising:

an X-Ray source;

an X-Ray receptor;

the X-Ray source and the X-Ray receptor being arranged to define animaging zone;

an X-Ray support base;

the source and the receptor being mounted on a common mounting membercarried on the X-Ray support base and moveable relative thereto foradjusting the relative positions of the patient support table and theX-Ray imaging zone for imaging selected parts of the patient;

the upper patient support portion of the patient support table beingcantilevered from the table support base in a direction longitudinal ofthe axis so as to extend into the bore from one end of the magnet to theimaging zone and also be used with an X-Ray tube under the upper patientsupport and a detector above the upper patient support;

the X-Ray imaging system and the patient support table being mounted forrelative movement of one relative to the other such that the upperpatient support portion can cooperate with the magnet during magneticresonance imaging and can cooperate with the X-Ray imaging system duringX-Ray imaging.

The system can be used to obtain MR images of all parts of the anatomy.This can be done in two ways; either by moving the patient support inthe bore or by fixing the patient support and stopping the magnet atdifferent points along the table.

Preferably there is provided a room containing the patient support tableand the X-Ray imaging system, the room having doors through which themagnet can pass and wherein the magnet support is arranged to move themagnet to a position outside the doors when magnetic resonance imagingis complete.

Preferably the X-Ray support base is moveable relative to the patientsupport table between an imaging position in which the patient supportportion is located in the imaging zone of the X-Ray imaging system and aremote position in which the X-Ray imaging system is removed from thetable a distance such that the magnet can be moved to the imagingposition of the magnet.

Preferably the X-Ray support base is movable in a direction generally toone side of the longitudinal direction of the table.

Preferably there is provided at least one additional X-Ray imagingsystem. If two are used they are preferably in a bi-planar arrangement.In this case, preferably both the X-Ray imaging systems are movablerelative to the patient support table and wherein one of the X-Rayimaging systems is movable in a direction generally away from the otherwith one X-Ray imaging system being mounted on floor and the other X-Rayimaging system being mounted from an overhead support and the otherX-Ray imaging system including overhead rails.

Preferably the X-Ray imaging system is mounted on a pivot for movementrelative to the patient support table.

In one arrangement, the patient support table rotates about a verticalaxis through an angle preferably of the order of 90 degrees from a firstangular position for co-operation with the X-Ray imaging system to asecond angular position for cooperation with the magnet.

Preferably the patient support portion of the patient support table ismounted for adjustable movement relative to the table support base foruse in moving the patient for X-Ray imaging and the movement can be usedfor adjustment of the anatomy in the bore of the magnet when the magnetis in the magnetic resonance imaging position over the patient support.When the magnet is over the patient support the patient supportadjustment can be disabled so as not to interfere with the bore of themagnet.

Preferably the upper patient support portion is removable from the tablesupport base and the table support base includes registration memberswhich allow engagement thereon only of an upper patient support portionwhich is configured to match the registration members so as to preventuse of an upper patient support portion which is incompatible with themagnetic field or with X-Ray.

Preferably the patient support table has side rails movablelongitudinally of the upper patient support portion for supportingaccessories and the side rails are limited in movement such that theyare prevented from impacting on the magnet when the magnet is in theimaging position.

Preferably each of the side rails includes an end stop member operableto halt longitudinal movement of one of the accessories along the railand potentially off of the end of the rail.

Preferably each of the accessories to be supported on the rails includesa pair of locking members at spaced positions along the rails to ensurethat the accessory is held in place at two spaced positions and isprevented from leaving the rail under magnetic attraction force. Thisgives redundancy to the locking mechanism for added safety.

Preferably there is provided a safety control system for controllingmovements of the magnet, the patient support table and the X-Ray imagingsystem.

Preferably the safety control system is arranged to prevent forwardmovement of the magnet into the room in the event that the patientsupport table and/or the X-Ray imaging system are not in a parkposition, which is a position where the magnet can safety move to themagnetic resonance imaging position without adversely affecting eitherthe patient support table and/or the X-Ray imaging system.

Preferably the safety control system is arranged to operate forwardmovement of the magnet up to a halt position spaced from the end of theupper patient support portion of the patient support table at which themagnet automatically is halted to ensure that there will be no collisionwith the magnet before proceeding forward.

Preferably the patient support table is operable to adjust the upperpatient support portion when the magnet is in the halt position andwherein the patient support table is prevented from adjusting the upperpatient support portion when the magnet is moved forwardly of the haltposition.

Preferably the safety control system is arranged to allow retractionmovement of the magnet at times when forward movement is enabled anddisabled. Also the safety control system is preferably arranged tooperate retraction movement of the magnet up to a halt position spacedfrom the end of the upper patient support portion of the patient supporttable at which the retraction movement automatically is halted.

Preferably the safety control system includes a status display for anoperator which includes indication of:

The state of enablement of movement of the magnet for all possiblemovements;

The state of the X-Ray imaging system and patient support tableincluding being in the park position;

Enablement of movement of the X-Ray imaging system including individualcomponents of the system;

Enablement of movement of the patient support table;

Components of the X-Ray imaging system and/or patient table beingpowered down either manually or automatically to reduce imagingartefacts from noise sources in the X-Ray imaging system and/or patienttable in the MR images during MR imaging.

Preferably the safety control system is arranged to power downcomponents of the X-Ray imaging system to reduce MR imaging artefactsduring the MRI by removing power to all components within the room withthe exception of those necessary to maintain the fast transition from MRimaging to X-Ray imaging including the temperature control of X-Rayreceptors of the X-Ray imaging system.

According to a second aspect of the invention there is provided anapparatus for imaging of a part of a patient comprising:

a patient support table, the patient support table comprising;

a table support base for mounting in fixed position in an imaging suite;

and an upper patient support portion on which the patient can lie withthe part of the patient exposed for imaging;

the upper patient support portion being mounted for controlled movementthereof relative to the table support base;

a magnetic resonance imaging system for obtaining images of the part ofthe patient, the magnetic resonance imaging system comprising:

a magnet for use with a control system for controlling and varying themagnetic fields,

a radio frequency transmission and detection system for eliciting anddetecting from the part of the patient nuclear magnetic resonancesignals, in response to the magnetic fields, including RF coils arrangedto be located adjacent to the part of the patient;

and a computer and display monitor for decoding and displaying an imageobtained from the detected signals;

the magnet defining a coil surrounding a horizontal axis and defining acylindrical bore extending between axial ends of the coil of the magnetwith an imaging zone part way along the bore between the ends;

the upper patient support portion of the patient support table beingcantilevered from the table support base in a direction longitudinal ofthe axis so as to extend into the bore from one end of the magnet to theimaging zone;

wherein the magnet is mounted on a magnet support arranged so that themagnet is movable between a magnetic resonance imaging position in whichthe magnet bore surrounds the patient support portion while the patientsupport portion remains supported on the table support base and a remoteposition in which the magnet is removed from the upper patient supportportion by a distance such that the upper patient support portion is outof the strong magnetic field of the magnet;

and an X-Ray imaging system comprising:

an X-Ray source;

an X-Ray receptor;

the X-Ray source and the X-Ray receptor being arranged to define animaging zone;

an X-Ray support base;

the source and the receptor being mounted on a common mounting membercarried on the X-Ray support base and moveable relative thereto foradjusting the relative positions of the patient support table and theX-Ray imaging zone for imaging selected parts of the patient;

wherein the upper patient support portion is removable from the tablesupport base and wherein the table support base includes registrationmembers which allow engagement thereon only of an upper patient supportportion which is configured to match the registration members so as toprevent use of an upper patient support portion which is incompatiblewith the magnetic field.

According to a third aspect of the invention there is provided anapparatus for imaging of a part of a patient comprising:

a patient support table, the patient support table comprising;

a table support base for mounting in fixed position in an imaging suite;

and an upper patient support portion on which the patient can lie withthe part of the patient exposed for imaging;

the upper patient support portion being mounted for controlled movementthereof relative to the table support base;

a magnetic resonance imaging system for obtaining images of the part ofthe patient, the magnetic resonance imaging system comprising:

a magnet for use with a control system for controlling and varying themagnetic fields,

a radio frequency transmission and detection system for eliciting anddetecting from the part of the patient nuclear magnetic resonancesignals, in response to the magnetic fields, including RF coils arrangedto be located adjacent to the part of the patient;

and a computer and display monitor for decoding and displaying an imageobtained from the detected signals;

the magnet defining a coil surrounding a horizontal axis and defining acylindrical bore extending between axial ends of the coil of the magnetwith an imaging zone part way along the bore between the ends;

the upper patient support portion of the patient support table beingcantilevered from the table support base in a direction longitudinal ofthe axis so as to extend into the bore from one end of the magnet to theimaging zone;

wherein the magnet is mounted on a magnet support arranged so that themagnet is movable between a magnetic resonance imaging position in whichthe magnet bore surrounds the patient support portion while the patientsupport portion remains supported on the table support base and a remoteposition in which the magnet is removed from the upper patient supportportion by a distance such that the upper patient support portion is outof the strong magnetic field of the magnet;

and an X-Ray imaging system comprising:

an X-Ray source;

an X-Ray receptor;

the X-Ray source and the X-Ray receptor being arranged to define animaging zone;

an X-Ray support base;

the source and the receptor being mounted on a common mounting membercarried on the X-Ray support base and moveable relative thereto foradjusting the relative positions of the patient support table and theX-Ray imaging zone for imaging selected parts of the patient;

wherein there is provided a safety control system for controllingmovements of the magnet, the patient support table and the X-Ray imagingsystem.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an Angiography room showing a patienttable, an MRI magnet movable into a position for imaging the patient onthe table and an arrangement for moving an X-Ray system.

FIG. 2 is an isometric view of a table for mounting the patient, thebase being omitted for convenience of illustration, and showing the RFcoil construction for imaging of the upper torso of the patient.

FIG. 3 is an isometric view on an enlarged scale of a portion of thetable of FIG. 2 and showing an insert portion for insertion into thereceptacle in the mattress when the posterior coil portion is removed.

FIG. 4 is an isometric view on an enlarged scale of a portion of thetable of FIG. 2.

FIG. 5 is an exploded view of the table of FIG. 2.

FIG. 6 is an isometric view of a table for mounting the patient, thebase being omitted for convenience of illustration, and showing the RFcoil construction for imaging of the head of the patient.

FIG. 7 is an exploded view of the table of FIG. 6.

FIGS. 8A and 8B are schematic plan views of the imaging system of FIG. 1showing the system in a first position for MR imaging and in a secondposition for X-Ray imaging.

FIG. 9 is a schematic block diagram of a safety system for use with theimaging system of FIG. 8.

FIG. 10 is an enlarged plan view of the table of FIG. 8A showing aregistration system for ensuring that only MR-compatible table tops areused with the table.

FIGS. 11A and 11B are schematic plan views of a modified arrangement ofthe imaging system of FIG. 1 again showing the system in a firstposition for MR imaging and in a second position for X-Ray imaging.

DETAILED DESCRIPTION

Reference may be made to the abovementioned Published PCT ApplicationWO07147233A1 of the present Applicants published Dec. 27, 2007 andentitled ROTATABLE INTEGRATED SCANNER FOR DIAGNOSTIC AND SURGICALIMAGING APPLICATIONS in which are disclosed details of the constructionof an MRI magnet suitable for use in the present arrangement. Thedisclosure of this document is incorporated herein by reference.

In FIG. 1 is shown an arrangement for carrying out Magnetic ResonanceImaging and X-Ray imaging of a patient while the patient remainsstationary on a patient support table. The arrangement provides a room 1in which is mounted a patient support table 10 with doors 2 at one sideof the room for entry into the room of the magnet 3 of an MR imagingsystem from a magnet bay 1A. The room contains an X-Ray imaging system 4mounted on rails 5 and includes an X-Ray transmitter 6 and receiver 7mounted on a C-shaped support 8. The X-Ray system is of a conventionalconstruction commercially available from a manufacturer such as Siemens.The table 10 described and illustrated herein is used in an arrangementwhere the patient remains in position on the table while imaging iseffected using MRI and X-Ray.

Additional unique multi-room layouts, configurations and applicationsare possible when a rotating MRI system is designed. In this case, thefollowing multi-room configurations are used as examples to illustratethe variety of applications which are possible, with all of theseapplications being financially beneficial to the healthcare industry.

In general, the magnet system 3 moves into a room within a relativelyshort time such as 1 minute, and the doors 2 open within a few seconds,so the limiting factor on effectiveness of usage of the magnet system isproviding the patients into and out of the room, prepping the patientsif required, and discussing the imaging with the patients. It is knownthat a reasonable amount of time per imaging event is 60 minutes, andtherefore the movement of the MRI scanner into and out of a room is notthe limiting time value. The following configurations are now possible:

The system can be used with a three room diagnostic configuration inwhich the central magnet holding bay 1A houses the magnet and thediagnostic patients are organized in the three rooms including the room1 and a further room not shown beyond the bay 1A. The doors 2 to room 1open, the magnet holding bay 1A becomes par of room 1. When the magnetmoves to the second room, the magnet may not move but may extend itsdiagnostic table, the patient lies on the diagnostic table, imaging isperformed, no need to do intervention is found, the patient exits thediagnostic table and the magnet moves back into the holding bay, readyfor use by one of the other rooms. The magnet then may draw in itstable, rotates to the doors for that room, and the process for the otherroom begins. In this case, the magnet does not move in a translationaldirection, such as on rails, but simply rotates to face one room andthen the other room.

The system can be used with a two room system with the two rooms facingat an angle to each other (for example, 90 degrees). In this case, themagnet both rotates and translates. There is a central magnet holdingroom, with doors in each of the two 90 degree directions, and the magnetcan rotate its diagnostic table in whichever direction is required, orcan rotate to allow the opposite end of the magnet to enter the roomfirst. This approach allows existing diagnostic functionality andapplications to be used in either room, or allows both rooms to serve asintra-operative rooms without any significant change to magnet controlsand monitoring. This two room corner system cannot be done without arotating magnet.

The system can be suspended from the ceiling or mounted on a floormounted bearing, with either system providing rotation of the magnet.The MRI system may also be suspended from the ceiling on rails, suchthat it can also be translated in space using the rail system. Therotational mechanism can either be located between the magnet and therails, or above the rails. The below track and above track rotators havedifferent properties for different configurations. The below trackrotator allows for easiest upgrade of existing sites, whereas the abovetrack rotator works like a roundhouse in a railway yard, in that therail, MRI system and all associated systems are rotated.

Turning now to the arrangement shown in FIGS. 1 and 8 including theX-Ray system which co-operates with the moving magnet described above,the system consists of the movable magnet integrated with an X-Raysystem such that the patient can be imaged by either modality on thesame table. The patient does not move from the table.

The MR is a high-field (e.g. 1.5 T or 3 T) magnet that moves on overheadrails between the two or more rooms as described above. In the systemdescribed, one or more of these rooms contains an X-Ray system, either asingle-plane or a bi-plane. When the magnet is moved out of the X-Rayexamination room and a set of RF and X-Ray shielded doors is closed, theexamination room functions as a conventional X-Ray lab and can be usedwith conventional equipment. In particular, X-Ray guided interventionsand surgeries may be performed.

The arrangement may be used in a typical three room configuration withthe Angiography Room (AR) on the left, a Diagnostic Room (DR) in themiddle, and an Operating Room on the right. The magnet moves on overheadrails between the rooms and can image in each.

When MR imaging is required, the X-Ray equipment is safely stowed, thedoors open, and the magnet is brought into the room over the patient onthe table. The RF shield encompasses the AR so all the equipment in theX-Ray examination room is made RF-quiet to prevent distortions fromnoise or interference with the MR imaging. MR imaging can then beperformed. Afterwards, the magnet is removed from the room, the doorsclosed, and the X-Ray equipment is returned to its working position.

The MR scanner is used to provide information complementary to thatobtained using X-Ray. It can be used, for example, to perform a baselineassessment prior to intervention as well as to perform apost-intervention assessment. The same applies for surgeries. Such anassessment may include perfusion and viability studies of, for example,the heart or of the brain.

As example workflows for the system, consider elective procedures andemergency cases, such as acute stroke or acute coronary syndromes.

In the Elective Procedure Workflow, a preliminary, baseline MR scan canbe obtained with the patient either in the diagnostic room or in theangiography room housing the X-Ray equipment (also known as the Angioroom or AR); this is basically a pre-procedure MR scan. The objective isto measure baseline parameters that are clinically relevant. For acardiac procedure, this may include baseline cardiac function andmyocardial viability.

After the MR scan, the patient is transferred to the angiography room ifMR imaged in the diagnostic room, or simply remains on the table ifalready in the Angio room, where coronary or cerebral angiography andangioplasty, followed by stent placement are conducted, if required, inthe customary fashion under X-Ray fluoroscopy.

The MR Scanner magnet enters the angiography room and acquires theappropriate MR images. After reviewing the MR data and possiblycorrelating with the X-Ray data, the interventionist can eitherdischarge the patient or continue treatment.

In the emergency Case Workflow, the patient is admitted and undergoespreparation in the Emergency room (both groins shaved, screening for MRexamination, metal check, etc.). The patient is brought to AR (in thecase of an acute myocardial infarction diagnosed by ECG) and vascularaccess via the groin is established. MR Imaging could take place in theAR for baseline assessment in order to minimize movement of the acutepatient. The scanner is brought into the AR for MR measurement ofbaseline cardiac function and perfusion imaging in a cardiac case. Inthe case of stroke, the MR images will reveal if interventional therapyis indicated. In both cases, MR baseline imaging is completed andprocessed in a minimum time period. In both stroke and cardiac patientsangiography and intervention (angioplasty, thrombectomy, or delivery ofclot-busting drugs at the site of occlusion) are performed in thecustomary fashion, under X-Ray fluoroscopy, if so indicated.

The MR Scanner is brought into the AR for subsequent MR imagesacquisition. After reviewing the MR images and possibly correlation withthe X-Ray data, the interventionist will discharge the patient orcontinue with treatment.

In the arrangement for moving the X-Ray system as shown in FIGS. 1 and 9the MR enters the X-Ray examination room and moves over the head end ofthe table 10. Since the path of the MR may pass right through thelocation of the C-arm stands, the latter must be moved before the magnetmay enter. Depending on need, a floor-mounted C-arm stand may be movedon floor rails, floor turntable, or a boom mounted on the floor or wall.Depending on need, a ceiling-mounted C-arm stand may be moved usingextended rails to park it at the foot end of the table, by mounting thestand rails on a platform suspended from the movable magnet rails orindependent rails, or by fixing the stand rails on a platform with atelescopic arm to move them laterally.

Using a solution to move a floor-mounted stand together with a mover fora ceiling mounted stand provides a mechanism to move a bi-plane system.The mover can provide a mounting position of the single plane orbi-plane at some non-zero angle to the MR rails, e.g., 90 degrees.

The Patient Handling System or support table is shown in FIGS. 2 to 7 asindicated generally at 10. The patient support table includes a base 11of a conventional construction which allows the base to move a patientsupport portion 12 to required locations in height and in orientation.Suitable drive mechanisms and couplings are known in the art and thusare not required to be described herein. At the top of the base 12 ismounted the patient support portion in the form of a generally planarbody 12 formed of a fiber reinforced plastics material so as to define asurface area sufficient for supporting the patient while lying on thepatient support portion. Thus as best shown in FIG. 5, the patientsupport 12 includes a rear edge 13 at or beyond the feet of the pronepatient together with two side edges 14 and 15 spaced by a distancesufficient to receive and contain the legs, body and arms of the patientto be supported by the support portion. At a forward end 16 is provideda forwardly extending narrower portion 17 for underlying the head of thepatient. Thus the width through the side edges 14 and 15 issubstantially constant up to the edge 16 where the support portionnarrows in width generally at a location adjacent the shoulders of thepatient to provide a narrower plate portion 17 of sufficient width forgenerally supporting the head of the patient.

On top of the patient support portion 12 is provided a mattress 18 whichis shaped to overlie the patient support portion 12. Thus the mattresshas a rear edge 19 which is located at the edge 13 of the portion 12 andtwo side edges 20 and 21 which are adjacent the side edges 14 and 15. Astep portion 22 is provided in the mattress where the mattress increasesin width. Thus the sides include side portions 20A and 21A of reducedwidth which are located at the positions intended to be inserted intothe cylindrical bore of an MRI magnet. The wider portions of themattress beyond the step 22 are generally intended to remain outside themagnet bore so that these portions can be of increased width allowingmore stability for the patient. The portion to be inserted into the boreis cantilevered forward from the base 11 so that the whole of the baseis located beyond the step 22 within the area of the wider part of themattress.

The structural support for the patient is provided by the supportportion 12 which is formed of a fiber reinforced resin material wherethe fibers are laid in sheets and infused by the resin material toprovide a flat structural member of sufficient strength to carry theweight of the typical patient. In order that the patient support portionbe formed of a material which does not interfere with the operation ofthe magnet or the generation and acquisition of the necessary signalsused in magnetic resonance imaging, the fiber reinforcement selected foruse in the structure of the portion 12 is a fiber which has sufficientstrength to provide the necessary resistance to bending but a fiberwhich is non-electrically conductive. Thus carbon fibers cannot be usedsince long carbon fibers generate or allow currents to flow within thestructure of the portion and such currents will interfere with thenecessary signals. The currents are generated by the high magneticfields within the magnet and by the electro magnetic signals which aregenerated within the magnet for use in the magnetic resonance imaging.Typically aramid fibers such as Kevlar™ can be used in replacement forthe carbon fibers typically used in such structures.

The mattress is formed of a stiff foam material encased by a skin toprovide an exterior surface which is resistant to fluids and can bereadily cleaned for sterilization to be used in clinical situations. Themattress extends from a step 22 through to a forward edge 25 located atthe end edge 16. The mattress does not include a portion extendingbeyond the end edge 16 into the area of the plate 17.

The mattress is formed in two layers of formed material to provide atypical thickness of the order of two inches. The second or lower layerof foam is omitted in the area between the end edge 25 and a location 26to define a receptacle 27 within the mattress at the upper surface ofthe portion 12. On top of the receptacle is provided a second layer offoam material so that the receptacle is spaced from the body of thepatient by a layer of foam, albeit a thinner layer of foam so that thepatient is comfortably supported throughout the full length of thepatient despite the presence of the receptacle underneath the chest areaof the patient.

As shown in FIG. 7, the receptacle 27 can be filled by an insert portion28 formed of the same foam material with a covering skin. The portion 28is shaped to fill the receptacle so that it is rectangular with twoparallel sides allowing to slide between the edge 25 of the receptacleand the end 26 of the receptacle. The sides of the insert portion 28carry hook and fastener connection strips 29 which cooperate withsimilar strips 30 on the edge 26 and on a depending flap 31 at the end25. In practice the Insert piece 28 can be inserted into place when thepatient is removed since the table is to be set up for imaging eitherthe head or the chest of the patient and in the case where the imagingis to be of the head, the chest coil is omitted so that in this case theinsert piece 28 is placed onto the support portion 12 and the mattressplaced on top of it.

When the imaging is to be of the chest, the anterior chest coil 31 isarranged to be placed on top of the chest of the patient when in placefor imaging on the mattress and also the posterior coil 32 is arrangedto be inserted into the receptacle 27. In order to protect the coil 32and in order to ensure that the mattress remains properly flat over thereceptacle 27, a flat rectangular sleeve 33 is provided which isinserted in place under the mattress when the coil 32 is to be used.Thus when the table is set up for the imaging of the chest, the insertpiece 28 is omitted and in its place the sleeve 33 is inserted. Thisallows the posterior coil 32 to slide into place through a slot shapedopening 34 in one side of the sleeve 33 at the side of the mattress 18.The coil 32 is shaped to fit simply as a sliding fit into the interiorof the sleeve. Thus when it is intended to carry out magnetic resonanceimaging, the posterior coil 32 can simply slide into place allowing thepatient and the cantilever portion of the table to slide into themagnetic bore to carry out the imaging.

When the imaging is complete and the patient is to be imaged by an X-Raysystem, the coil 32 can simply be removed by pulling the coil out of theopening 34 of the sleeve 33. The anterior coil 31 can also simply beremoved from the top of the patient chest so that all coil portions areremoved from the table allowing X-Ray imaging to be carried out withoutany interference from any metal components in the table.

As best shown in FIG. 3, the cable from the coil 32 which transmits thereceived signals to the control system of the magnetic resonance imagingapparatus is shown at 36 and is arranged on the coil at the forward endof the coil exiting from a front surface 32A of the coil immediatelyadjacent the side surface 32B of the coil. Thus the cable 36 extends atthis position forwardly from the coil 32. The sleeve 33 has a slot 33Alocated in the front surface 33B of the sleeve adjacent the opening 34.This allows the coil to be inserted through the opening 34 with thecable 36 and its innermost end 36A extending through the slot 33A andthus extending forwardly from the coil and forwardly from the sleeve 33.The cable thus emerges beyond the end 25 of the mattress 18 and no partof the cable extends beyond the side edge 20A of the mattress 18. Thecable 36 can thus be laid so that it extends beyond the end 25 whereuponit curves upwardly and rearwardly to form a cable portion 36B passingover the shoulder of the patient and along the body of the patient at ajunction between the arm and body of the patient to a position beyondthe arm where the cable includes a portion 36C lying over the mattressand particularly the wider part of the mattress beyond the shoulder 22.In this way the cable can be directed so that it is properly controlledand laid in position by the operators prior to the imaging processtaking place. The cable is properly managed as it passes over thepatient and the cable has no possibility of falling outwardly in anuncontrolled manner from the table. No part of the table projects beyondthe sides of the mattress and the support portion 12 so that these canbe of the maximum dimension allowable to enter the bore of the magnet.

The table further includes arm engagement members 40 and 41 arranged tocontain the arms of the patient to ensure that they are retained on themattress and cannot fall to the sides as the patient resides on thesupport during the imaging process. Even though the table remainsstationary during the imaging both by the magnetic resonance imagingsystem and by the X-Ray system, it is necessary to confine the patientso that the patient cannot move side to side and cannot drop one arm tothe side of the table during the imaging process.

The arm engagement members best shown in FIG. 5 include a generallyupstanding board 42 which has a length from a rear end 43 to a forwardend 44 which is sufficient to extend along substantially the whole ofthe arm of the patient from the hand to the shoulder. The board iscontoured with a generally upstanding portion and an upper portion whichis inclined inwardly and upwardly so as to form a slight channel shapebetter confining the arm of the patient. The board is attached to amounting plate 45 which is a flat plate with side edges 46 and 47 and aninner edge 48. The plate 45 includes an upturned flange portion 49standing upwardly from the plate and having a length equal to the lengthof the plate between the edges 46 and 47. At the top of the flangeportion 49 the board 42 is attached as an integral connection but theboard extends from the flange 49 forwardly to the forward edge 44. Thusthe plate 45 is restricted to a distance so that the front edge 47 isrecessed from the front edge 44 of the board. The length of the plate 45is such that it can be inserted underneath the patient between themattress and the flat support 12 so that the plate is pinched by theweight of the patient holding the board in place against movementlongitudinal or outward to the side. The length of the mounting plate 45however, is restricted so that it terminates at a position just beyondthe edge 26 of the mattress so that the plate does not extend under thesleeve 33 or into the area of the coil 32. Thus the arm support board 42is cantilevered forwardly from this plate and the plate itself does notenter into the area of the imaging defined by the coil. Of course thecoil is located at the required position for the part of the patient inthe chest to be properly imaged both in the magnetic resonance imagingsystem and in the X-Ray system.

When the coil 32 is removed, the arm boards remain in place so that thepatient can remain lying in place on the mattress and the patientremains confined by the arm engagement members 40 and 41 as the magnetis removed and the X-Ray system is moved into place. The X-Ray processcan therefore take place and therefore the boards hold the patient inplace while the mounting plates 45 are located at a position which doesnot interfere with the X-Ray process. As shown in FIGS. 3 and 5, duringX-Ray imaging of the chest the head of the patient is simply supportedon a mattress extension portion 50 which is carried on a plate portion51. This plate portion has a width slightly less than the width of thesupport portion 12. Thus the plate portion 51 includes a rear edge 51Aand a parallel front edge 51B. The plate portion also includes one sideedge 51C on the side opposite the cable 36. At the cable 36, the plateprovides a side edge 51D which includes a recess 51E into which thecable 36 is inserted. The mattress portion 50 also includes a rear edge50A coincident with the edge 51A. The mattress portion 50 also includesa front edge 50B coincident with the edge 51B and side edges 50C and 50Dcoincident with the side edges 51C and 51D. Again therefore the mattressportion includes a recess 50E into which the cable is inserted. Theplate 51 is carried on a pair of guides 52 and 53 which form a slot forsliding over the plate portion 17 at the side edges thereof. Thus theplate 51 slides over the top of the plate portion 17 and is held inplace by the slot guides on the underside together with a screw clamp 54which pinches the edge of the plate portion 17 to ensure that thesupport plate 51 remains in place at the end of the mattress. Themattress portion 50 is then placed on top of the plate portion 51. Themattress 18 and the mattress portion 50 are conveniently held in placeby hook and loop fastener strips 56 located at suitable locations on theparts of the support 12 on which they are mounted. The mattress is thusproperly held in place allowing the patient to be moved on top of themattress without the danger of the mattress sliding to one side. Thus asshown in FIG. 3, when the imaging is carried out at the chest area, theheads of the patient simply rests upon the mattress portion 50 which maybe supplemented by a cushion or other comfort receptacle as required.

Turning now to FIGS. 6 and 7, the table is shown in these figuresconfigured for imaging of the head. During the imaging of the head, thechest coils are of course fully removed. In addition the plate 51 andthe mattress portion 50 are also removed allowing a more effective andaccurate supporting of the head for imaging of the head. Thus there isprovided a head support generally indicated at 70 and a head coil 71including an anterior portion 72 and a posterior portion 73. The headsupport 70 comprises a channel member 74 which is shaped to receive therear of the head of the patient and hold this supported at all timesduring the imaging process. The head support 74 comprises a simplechannel or it can comprise a flexible receptacle portion with strappingto hold the head more effectively in place. Either type of head supportis mounted on a bracket 75 carried on a slot shaped mounting member 76with bottom slot portions 77 and 78 which engage onto the edges of theplate 17 in the same manner as previously described in respect of theplate 51. Thus the slot shaped mounting member 76 slides into place andcan be fastened in place by a fastening screw 79. When in place, a frontedge 80 of the mounting 76 butts against the edge 16 of the support 12at the bottom of the plate portion 17. The channel member 74 is thuscantilevered forwardly from the mounting brackets 75 to a front edge 82spaced forwardly of the bracket and forwardly of the edge 16 to aposition overlying the plate 17 but spaced upwardly from the plate 17.

The posterior coil portion 73 includes a curved upper surface 73A whichfollows approximately the outer surface of the channel member 74 so thatit can pass over the underside of the channel member 74 in a slidingaction longitudinally of the head of the patient.

It will be appreciated that the shapes of the surface 73A and the bottomsurface of the channel 74 need not be closely accurate provided theshapes provides sufficient clearance to allow sliding action to occur.However it is preferred that the coil be as close as possible to therear of the head of the patient so that the channel member 74 is formedof a thin material sufficiently strong to support the weight of the headand the surface 73A is closely adjacent the rear surface of the supportchannel 74.

The posterior coil 73 is carried on a support bracket 85 which alsoincludes a slot shape mounting 86 for sliding onto the plate portion 17at a position beyond the mounting 75 and its slot shaped mountingportion 77. As best shown in FIG. 6, therefore, the head support channel74 is located inside the posterior coil 73 and the mounting brackets 75and 85 are arranged so that they both fit onto the plate 17 with themounting bracket 85 in front of the bracket 75. Thus the bracket 75 canremain in place and the support 73 can hold the head of the patientwhile the posterior coil portion is moved into place or is removed fromplace.

The anterior coil portion is mounted on the posterior coil portion so itcan slide into place as a common structure or it can be removed andplaced onto the posterior coil portion when the posterior coil portionis already installed.

As shown in FIG. 7, there is a sliding interconnection between the rearsurface of the posterior coil 73 and the top of the bracket 85 allowingthe posterior coil to be removed from the bracket.

The patient handling system thus contains the following key components:the patient table 11, the head holder 73, and MR imaging coils. Thesystem, including integration of the key components, is speciallydesigned to permit imaging with both MRI and X-Ray imaging modalities,while maintaining sufficient image quality and workflow.

The patient table is designed to allow the patient to be scanned withboth MR and X-Ray imaging modalities. The patient table is comprised oftwo major components: the table pedestal and the tabletop. The tabletopis fully MR and X-Ray compatible; the table pedestal does not adverselyimpact image quality during MR scanning (i.e. does not impacthomogeneity of magnetic field), the pedestal also does not experiencesignificant forces from the magnetic field. The tabletop is positionedso that the table pedestal (which is also not X-Ray compatible) is at adistance that is sufficiently away from the imaging site. The tabletopintegrates the head holder, arm boards and MR imaging coils.

The head holder supports the patient's head during the procedure andmust also be MR and X-Ray compatible. The head holder integrates intothe patient table in a manner that is very efficient to position andremove. The MR imaging head coils may also be integrated with the headholder and are easily positioned and removed at the imaging site.

The MR imaging coils consist of head coils (for imaging the head andupper spine), as well as coils for imaging other areas of the body (e.g.cardiac coils for imaging chest). MR coils are not X-Ray compatible andthus are positioned and removed from the imaging area when switchingbetween imaging modalities without having to move or interfere with thepatient. An example is the MR coils used for cardiac imaging, whichconsist of an anterior (placed on top of the patient's chest) and theposterior coil (placed underneath the patient's back). The anterior coilcan simply rest on the patient; the posterior coil is integrated intothe tabletop in a variety of options: underneath the tabletop, withinthe structure of the tabletop, or on top of the tabletop, which alsoincludes integrating the posterior coil into the tabletop mattress. Allof these methods are designed such that the coils are easily andefficiently positioned and then removed from the imaging area.

During certain medical procedures, both X-Ray and MR imaging modalitiesmay be employed, at separate times during the procedure. Since MRI coilsare not X-Ray compatible, it is necessary to position and remove thecoils quickly and easily when switching between MRI and X-Ray imaging.For cases where it is necessary to keep the patient in a fixed positionduring the procedure, the imaging coils must also be positioned andremoved without moving or shifting the patient in any way. For example,cranial procedures will employ the head holder to secure the head of thepatient during the entire procedure. The MR imaging head coils will beeasily positioned around the head holder without moving the head holderor the patient's head in any way. A second example is proceduresrequiring chest/abdominal imaging. The anterior coil may be positionedon top of the patient; the posterior coil is positioned into a slot orcavity in the table top mattress, the tabletop itself, or below thetabletop. All methods of positioning the posterior coil maintain aconstant position for the patient.

The patient table consists of a table top that is completely MR andX-Ray compatible. The tabletop also enables the integration of variousMR imaging coils, such as head coils and cardiac coils, with the specialfeature of positioning and removing the coils without moving or shiftingthe patient in any way. Coil integration can involve a slot or cavitywithin the tabletop itself, or within the tabletop mattress.Alternatively, the coils can also be positioned underneath the table,through a mounting bracket or shelf component.

A special cavity insert device is also included to fill the void in thetabletop or mattress when the MR imaging coil is not in place; thisprovides additional structural strength.

There is provided reinforcing material around the coil cavity in thetable/mattress to provide for extra rigidity when switching between theimaging coils and the cavity insert. Alternatively, the cavity may belined with an inflatable pocket that upon inflation lifts the patientenough to easily insert and remove the coil to replace with cavityinsert. The tabletop also includes a means of easily positioning andremoving the head holder; this includes a ridge or ledge around the headend of the tabletop, where the head holder may slide on with a dovetailinterface. The imaging head coils also are integrated to the table inthis fashion.

The head holder and table adapter assembly include the head holder thatsecures the head during the procedure and also a table adapter thatsecures the head holder to the patient table and also provides a meansof adjusting the position/orientation of the head holder. The entireassembly is completely MR and X-Ray compatible. There are various meansof securing the patient's head, including a horseshoe head holder, asling/suspender head holder, and a head cradle. The horseshoe headholder includes a rigid frame that is cushioned by gel, foam, or airinflated pillows; the sides and top of the patient's head may besupported by a strap or by side cushions. The frame may also beadjustable for accommodating a large range in head sizes. Thesling/suspender head holder consists of soft material (e.g. fabric) thatis shaped into a sling to support the back and sides of the head. Thetop of the head may be supported by a fabric strap; foam padding mayinsert between layers of material in the sides of the sling to cushionthe head where the table adapter interfaces to the sling/suspender headholder. The head cradle is a scoop-shaped device that cradles the headand neck of the patient and includes foam or inflatable air pillows tocushion the back of the patient's head (for comfort) and also preventingthe patient from moving the head from side to side. One additionalfeature of the inflatable pillow is that the pillow may be deflated tobring the head down slightly so that it is even closer to the portion ofMR imaging head coil that is positioned directly underneath the head ofthe patient, which will increase MR image quality. The table adapter mayinterface to the head holder at various orientations, such as at thefront of the head holder (closest to the patient's head), at the back ofthe head holder (furthest from patient table), along the sides of thehead holder, or along the top of the head holder.

Turning now to FIGS. 8 and 9, there is shown schematically the apparatusfor imaging of a part of a patient which may be the head, chest or otherparts of the patient as required.

The apparatus includes the patient support table 10 as previouslydescribed. This includes the upper patient support portion 12 on whichthe patient can lie with the part of the patient exposed for imagingmounted on the table support base 11 which is mounted in fixed positionin the imaging suite.

The table can be for example of the type manufactured by Siemens whichincludes a main base 11 and an upper movable section 11A carried on thebase which can be moved side to side, front to rear and can be tiltedabout longitudinal and transverse axes. The movable section 11A carriesa replaceable table top 11B which can be selected from different designsdepending upon the intended use of the system. The details of this tablesystem are known to persons skilled in this art do that no furtherexplanation is required.

The magnetic resonance imaging system is also known and a systemmanufactured by IMRIS is available for this purpose. The magneticresonance imaging system includes, as is well known, the magnet for usewith a control system 3A for controlling and varying the magnetic fieldsand includes a radio frequency transmission and detection system foreliciting and detecting from the part of the patient nuclear magneticresonance signals, in response to the magnetic fields, including RFcoils 31 and 70 as previously described arranged to be located adjacentto the part of the patient.

The control unit 3A includes a computer and a display monitor 3B fordecoding and displaying an image obtained from the detected signals.

The magnet is of the type including a coil 3C surrounding a horizontalaxis and defining a cylindrical bore extending between axial ends of thecoil of the magnet with an imaging zone part way along the bore betweenthe ends.

The upper patient support portion 11B of the patient support table iscantilevered from the table support base 11 in a direction longitudinalof the axis so as to extend into the bore from one end of the magnet tothe imaging zone when the magnet is on the imaging position shown at 3Din FIG. 8A.

The magnet 3 is mounted on a magnet support 3G so that the magnet ismovable longitudinally along its axis between the magnetic resonanceimaging position 3D in which the magnet bore surrounds the patientsupport portion while the patient support portion remains supported onthe table support base 11B and a retracted position 3E and a remote parkposition 3F outside the doors 2 into the room 1A. In the remote parkposition, the magnet is removed from the upper patient support portion11B by a distance such that the upper patient support portion 11B is outof the strong magnetic field of the magnet. Although the cylindricalmagnet which moves along its axis is preferably used, other types ofmagnet and other moving directions may also be used in some arrangements(not shown).

The X-Ray imaging system 4 includes two X-Ray systems 4X and 4Y whichare typically arranged in a bi-plane arrangement as is well known. Eachincludes an X-Ray source 4A, an X-Ray receptor 4B mounted on an X-Raysupport base 4Z defining an imaging zone. The source and the receptorare mounted on a common mounting member carried on the X-Ray supportbase and moveable relative thereto for adjusting the relative positionsof the patient support table and the X-Ray imaging zone for imagingselected parts of the patient. The X-Ray system is again well known to aperson skilled in the art and a suitable system is available fromSiemens so that no further details are required.

The X-Ray imaging system and the patient support table are mounted formovement either the table or the X-Ray system such that the upperpatient support portion 11B of the table can carry the patient and canco-operate with the magnet during magnetic resonance imaging and cancooperate with the X-Ray imaging system during X-Ray imaging.

The system can be used to image in the MR system different parts of theanatomy. This could be done in two ways; either moves the patientsupport in the bore or fix the patient support and stop the magnet atdifferent points in the room.

The room 1 containing the patient support table and the X-Ray imagingsystem has doors 2 through which the magnet 3 can pass and the magnetsupport 3G is arranged to move the magnet to a position outside thedoors and into the room 1A for storage or for use in other suites, whenmagnetic resonance imaging is complete.

The relative movement of the table relative to the X-Ray system can becarried out in two different ways.

In FIGS. 8A and 8B, the table moves through 90 degrees to a positionshown at 11G in FIG. 8B where the table co-operates with the X-Raysystem 4 including the floor mounted first system 4Y and the overheadmounted rail system 4X. The systems 4X and 4Y can be moved from a parkposition into operating positions to carry out the imaging. The tablecan be moved to a required position relative to the systems 4X and 4Y toeffect accurate control of the location of the imaging on the patient onthe table.

In FIGS. 11A and 11B an alternative arrangement is shown in which thetable 11 remains at a position generally aligned with the axis of themagnet and instead the X-Ray system 4X and 4Y is moved. Thus the system4Y includes a support base 4C which is moveable on a pivot arrangementrelative to the patient support table 11 between an imaging position 4Dshown in FIG. 11B in which the patient support portion is located in theimaging zone of the X-Ray imaging system and a remote position 4E shownin FIG. 11A in which the X-Ray imaging system is removed from the tablea distance such that the magnet can be moved to the imaging position ofthe magnet. This movement can be obtained by mounting the conventionalX-Ray system on an arm 4G which pivots on the base 4C about a verticalaxis 4F on one side of the table. Thus the movement acts to move theX-Ray system to a position at the table in one position of the arm 4Gand moves the system to a position at maximum spacing from the table toone side of the table at 180 degrees to the arm position.

Thus the X-Ray support base is movable in a direction generally to oneside of the longitudinal direction of the table 11. The X-Ray system asshown includes 4X mounted in a bi-planar arrangement with the firstsystem 4Y. The system 4Y is mounted on overhead rails 4H to carry thesystem 4X longitudinally along the table in the direction opposite tomovement of the magnet. Other systems not shown may include furtherX-Ray planes.

Turning now to FIG. 107 the table 10 includes the base portion 11 and ahorizontal patient support portion 11A of the patient support tablewhich is mounted for adjustable movement relative to the table supportbase for use in moving the patient for X-Ray imaging. Thus the baseincludes controls 10A which are manually operable by the user to movethe table side to side and front to rear over limited distances and totilt the table about the longitudinal and transverse axes.

The upper patient support table includes a removable portion 11D whichis removable from the table support base which includes registrationmembers 11B which allow engagement of the table top 11D onto the basewhich is configured to match the registration members. Thus the base andthe top are arranged to ensure that only MR compatible table tops areused to avoid any possibility of a mistake so as to prevent use of anupper patient support portion which is incompatible with the magneticfield. The arrangement of registration members can of course vary and asshown they include a series of pins on the base which must be receivedin suitable openings 11D in the removable top. Other table tops whichare not suitable for the combined MR and X-Ray system, but may beavailable in the facility where the system is installed for use on othersimilar systems, cannot be mounted on the base because they do notinclude the registration holes.

The patient support table 11 has side rails 11X and 11Y on respectivesides of the table top which are provided to receive and supportaccessories 11Z. The rails are movable longitudinally of the upperpatient support portion but are limited in movement by fixed stops suchthat their ends 11S are prevented from entering the magnet when themagnet is in the imaging position 3D. Thus a stop arrangement 11R isprovided which limits the forward movement of the rail when the magnetis brought up to the imaging position over the table.

Turning now to FIG. 9, there is provided a safety control system 90 forcontrolling movements of the magnet 3 through a magnet mover system 91,the patient support table 10 through a table control 92 and the X-Rayimaging system through as system controller 93. The system 90 alsocontrols the position of booms 94A for auxiliary equipment 94B such asmonitors (shown in FIG. 8) through a controller 94. The doors 2 areactuated by a controller 95 operated by the system 90. The systemincludes inputs from position sensors 96 for the X-Ray system 4 andsensors 97 for the magnet 3. The system 90 also actuates an X-Ray shutdown controller 98 which activates a shut down mode of the X-Ray system.The system also includes a status display 99 which includes, forexample, LEDS 100 to 104 which display respectively as follows:100—magnet movement enabled; 101—X-Ray system operation enabled;102—X-Ray and table in park positions; 103—table movement enabled;104—X-Ray system powered down by the shut down controller 98.

The safety control system is programmed with the following functions:

-   -   1. It acts to control movement of the magnet and particularly to        prevent forward movement of the magnet into the room in the        event that the patient support table and the X-Ray imaging        system are not in a park position.    -   2. The underlying concept is that the safety system prevents        putting the system in a dangerous state where the X-Ray, MR and        related and other components such as the booms that contain the        monitors are physically moved to positions where they may        interact. That is the safety control system is arranged to        prevent dangerous configurations of equipment; for example the        C-arms of the X-Ray system being located in a high magnetic        field.    -   3. The system can be used to actively cause the X-Ray system to        move into parked position as the magnet comes forward.    -   4. It acts to operate forward movement of the magnet up to a        halt position 3E spaced from the end of the upper patient        support portion of the patient support table at which the magnet        automatically is halted. At this position the table can be        adjusted manually and checked by the operator to ensure that the        table is in an accurately required position. Thus minor        adjustment of the table to orient the table within the bore can        be effected although larger adjustments to a position which        would cause impact of the table and magnet can be prevented.        Thus the magnet is brought up to the halt position close to but        spaced from the table where the final adjustments can be made of        the patient, the RF coils 31 can be connected to the terminals        31A provided on the magnet and the table orientation can be        finely adjusted. When this is completed, the magnet is moved        forwardly to the imaging position.    -   5. It acts to prevent the patient support table from adjusting        the upper patient support portion when the magnet is moved        forwardly of the halt position so that movement of the table is        fixed and turned off when the magnet is in the magnetic        resonance imaging position.    -   6. It acts to power down the X-Ray imaging system through        controller 98 sufficiently to reduce RF noise during the MRI by        removing power to all components within the room with the        exception of those necessary to maintain temperature control of        X-Ray receptors of the X-Ray imaging system.    -   7. After the imaging is complete, it acts to operate retraction        movement of the magnet up to a halt position spaced from the end        of the upper patient support portion of the patient support        table at which the retraction movement automatically is halted.        At this position the patient can be checked and the RF coils can        be disconnected from the terminals 31A to ensure that the magnet        is free to be removed through the doors 2.    -   8. It ensures that the magnet is fully removed and the doors        closed before the X-Ray equipment can be moved from its park        position.    -   9. It provides a status display for an operator which includes        indication of:

Enablement of movement of the magnet;

The X-Ray imaging system and patient support table being in parkposition;

Enablement of movement of the X-Ray imaging system;

Enablement of movement of the patient support table;

The X-Ray imaging system being powered down to reduce RF noise duringthe MRI.

Therefore in general, a safety system is provided for the safe andeffective integration of the two modalities. There are a number ofhazards in the AR, such as: collision with moving stands, table, and MR;ferrous objects being drawn into magnet bore; and unwanted radiationexposure.

The global safety system is responsible for a number of aspects of thesystem:

Motion of the C-arms is disabled when unsafe to do so.

Motion of the table is disabled when unsafe to do so.

Forward travel of the MR is disabled when unsafe to do so.

The path from the magnet's home position in the DR to its imagingposition in the AR is divided into three zones:

Far Zone: the magnet and the C-arms are far enough apart that each mayoperate independently without safety concern. The patient table may movefreely.

Near Zone: the magnet is close enough to the C-arms that the C-arms mustbe safely parked and not move. The patient table may move freely.

Table Zone: the magnet is over the table, or nearly so. The C-arm standsmust be safely parked and not move. The table must be in the correctposition for MR imaging and must not move.

In the Near Zone, the C-arm stands must be safely parked and not move.If this is not the case, forward motion of the MR is interrupted,preventing the MR from entering the Near Zone. Similarly, at thetransition between the Near and Table Zones the condition that the tablemust be in the position for MR imaging (i.e. at correct height andlateral position to enter the magnet bore) is checked. If the table isnot in the correct position, the magnet may not move forward into thezone.

The ESCP (Equipment Safety Check Point) and PSCP (Patent Safety CheckPoint) divide the path into three zones: Far, Near, and Table.Interlocks prohibit the magnet from advancing into a zone if it isunsafe to do so.

The safety system controller communicates with the movable magnetcontroller, the RF door controller, the X-Ray equipment and the patienttable, as shown in FIG. 1. The signalling includes the followinginformation:

The moveable magnet controller sends the magnet zone and receives asignal indicating whether forward travel is permitted.

The door controller sends a signal indicating whether the door is openor closed.

The X-Ray controller sends information on the location of the C-armstands and table position, and receives signals indicating whether standmotion or table motion is permitted.

1. Apparatus for imaging of a part of a patient comprising: a patientsupport table, the patient support table comprising; a table supportbase for mounting in fixed position in an imaging suite; and an upperpatient support portion on which the patient can lie with the part ofthe patient exposed for imaging; the upper patient support portion beingmounted for controlled movement thereof relative to the table supportbase; a magnetic resonance imaging system for obtaining images of thepart of the patient, the magnetic resonance imaging system comprising: amagnet for use with a control system for controlling and varying themagnetic fields, a radio frequency transmission and detection system foreliciting and detecting from the part of the patient nuclear magneticresonance signals, in response to the magnetic fields, including RFcoils arranged to be located adjacent to the part of the patient; and acomputer and display monitor for decoding and displaying an imageobtained from the detected signals; the magnet defining a coilsurrounding a horizontal axis and defining a cylindrical bore extendingbetween axial ends of the coil of the magnet with an imaging zone partway along the bore between the ends; wherein the magnet is mounted on amagnet support arranged so that the magnet is movable longitudinallyalong its axis between a magnetic resonance imaging position in whichthe magnet bore surrounds the patient support portion while the patientsupport portion remains supported on the table support base and a remoteposition in which the magnet is removed from the upper patient supportportion by a distance such that the upper patient support portion is outof the strong magnetic field of the magnet; and an X-Ray imaging systemcomprising: an X-Ray source; an X-Ray receptor; the X-Ray source and theX-Ray receptor being arranged to define an imaging zone; an X-Raysupport base; the source and the receptor being mounted on a commonmounting member carried on the X-Ray support base and moveable relativethereto for adjusting the relative positions of the patient supporttable and the X-Ray imaging zone for imaging selected parts of thepatient; the upper patient support portion of the patient support tablebeing cantilevered from the table support base in a directionlongitudinal of the axis so as to extend into the bore from one end ofthe magnet to the imaging zone and also be used with an X-Ray tube underthe upper patient support and a detector above the upper patientsupport; the X-Ray imaging system and the patient support table beingmounted for relative movement of one relative to the other such that theupper patient support portion can cooperate with the magnet duringmagnetic resonance imaging and can cooperate with the X-Ray imagingsystem during X-Ray imaging.
 2. The apparatus according to claim 1wherein there is provided a room containing the patient support tableand the X-Ray imaging system, the room having doors through which themagnet can pass and wherein the magnet support is arranged to move themagnet to a position outside the doors when magnetic resonance imagingis complete.
 3. The apparatus according to claim 1 wherein the X-Raysupport base is moveable relative to the patient support table betweenan imaging position in which the patient support portion is located inthe imaging zone of the X-Ray imaging system and a remote position inwhich the X-Ray imaging system is removed from the table a distance suchthat the magnet can be moved to the imaging position of the magnet. 4.The apparatus according to claim 3 wherein the X-Ray support base ismovable in a direction generally to one side of the longitudinaldirection of the table.
 5. The apparatus according to claim 1 whereinthere is provided at least one further X-Ray imaging system forco-operation with the first in, for example, a bi-plane configuration.6. The apparatus according to claim 5 wherein the X-Ray imaging systemsare movable relative to the patient support table and wherein one of theX-Ray imaging systems is movable in a direction generally away from theother.
 7. The apparatus according to claim 6 wherein one X-Ray imagingsystem is mounted on floor and the other X-Ray imaging system is mountedfrom an overhead support.
 8. The apparatus according to claim 7 whereinthe other X-Ray imaging system includes overhead rails which are movedin a direction toward one side of the table.
 9. The apparatus accordingto claim 1 wherein the X-Ray imaging system is mounted on a pivot formovement relative to the patient support table.
 10. The apparatusaccording to claim 1 wherein the patient support table rotates about avertical axis from a first angular position for cooperation with theX-Ray imaging system to a second angular position for cooperation withthe magnet.
 11. The apparatus according to claim 10 wherein the patientsupport table rotates about through an angle of the order of 90 degrees.12. The apparatus according to claim 1 wherein the patient supportportion of the patient support table is mounted for adjustable movementrelative to the table support base for use in moving the patient forX-Ray imaging and wherein the movement is fixed and turned off when themagnet is in the magnetic resonance imaging position.
 13. The apparatusaccording to claim 1 wherein the upper patient support portion isremovable from the table support base and wherein the table support baseincludes registration members which allow engagement thereon only of anupper patient support portion which is configured to match theregistration members so as to prevent use of an upper patient supportportion which is incompatible with the magnetic field or with X-Ray. 14.The apparatus according to claim 1 wherein the patient support table hasside rails movable longitudinally of the upper patient support portionfor supporting accessories and wherein the side rails are limited inmovement such that they are prevented from impacting on the magnet whenthe magnet is in the imaging position.
 15. The apparatus according toclaim 1 wherein there is provided a safety control system forcontrolling movements of the magnet, the patient support table and theX-Ray imaging system.
 16. The apparatus according to claim 15 whereinthe safety control system is arranged to prevent forward movement of themagnet into the room in the event that the patient support table, theX-Ray imaging system and auxiliary equipment such as the booms thatcontain the monitors, X-Ray protection, or other equipment are not in apark position.
 17. The apparatus according to claim 15 wherein thesafety control system is arranged to move the patient support table andthe X-Ray imaging system into a park position on forward movement of themagnet into the room in the event that they are not already in the parkposition.
 18. The apparatus according to claim 15 wherein the safetycontrol system is arranged to control auxiliary equipment such as thebooms that contain the monitors, X-Ray protection, or other equipment bymoving them out of the way when the magnet approaches.
 19. The apparatusaccording to claim 15 wherein the safety control system is arranged tooperate forward movement of the magnet up to a halt position spaced fromthe end of the upper patient support portion of the patient supporttable at which the magnet automatically is halted to ensure that therewill be no collision with the magnet before proceeding forward.
 20. Theapparatus according to claim 19 wherein the patient support table isoperable to adjust the upper patient support portion when the magnet isin the halt position and wherein the patient support table is preventedfrom adjusting the upper patient support portion when the magnet ismoved forwardly of the halt position.
 21. The apparatus according toclaim 15 wherein the safety control system is arranged to operateretraction movement of the magnet up to a halt position spaced from theend of the upper patient support portion of the patient support table atwhich the retraction movement automatically is halted.
 22. The apparatusaccording to claim 15 wherein the safety control system includes astatus display for an operator which includes indication of: The stateof enablement of movement of the magnet for all possible movements; Thestate of the X-Ray imaging system and patient support table includingbeing in the park position; Enablement of movement of the X-Ray imagingsystem including individual components of the system; Enablement ofmovement of the patient support table; Components of the X-Ray imagingsystem and/or patient table being powered down either manually orautomatically to reduce imaging artefacts from noise sources in theX-Ray imaging system and/or patient table in the MR images during MRimaging.
 23. The apparatus according to claim 15 wherein the safetycontrol system is arranged to power down the X-Ray imaging system toreduce RF noise during the MRI by removing power to all componentswithin the room with the exception of those necessary to maintaintemperature control of X-Ray receptors of the X-Ray imaging system. 24.Apparatus for imaging of a part of a patient comprising: a patientsupport table, the patient support table comprising; a table supportbase for mounting in fixed position in an imaging suite; and an upperpatient support portion on which the patient can lie with the part ofthe patient exposed for imaging; the upper patient support portion beingmounted for controlled movement thereof relative to the table supportbase; a magnetic resonance imaging system for obtaining images of thepart of the patient, the magnetic resonance imaging system comprising: amagnet for use with a control system for controlling and varying themagnetic fields, a radio frequency transmission and detection system foreliciting and detecting from the part of the patient nuclear magneticresonance signals, in response to the magnetic fields, including RFcoils arranged to be located adjacent to the part of the patient; and acomputer and display monitor for decoding and displaying an imageobtained from the detected signals; the magnet defining a coilsurrounding a horizontal axis and defining a cylindrical bore extendingbetween axial ends of the coil of the magnet with an imaging zone partway along the bore between the ends; the upper patient support portionof the patient support table being cantilevered from the table supportbase in a direction longitudinal of the axis so as to extend into thebore from one end of the magnet to the imaging zone; wherein the magnetis mounted on a magnet support arranged so that the magnet is movablebetween a magnetic resonance imaging position in which the magnet boresurrounds the patient support portion while the patient support portionremains supported on the table support base and a remote position inwhich the magnet is removed from the upper patient support portion by adistance such that the upper patient support portion is out of thestrong magnetic field of the magnet; and an X-Ray imaging systemcomprising: an X-Ray source; an X-Ray receptor; the X-Ray source and theX-Ray receptor being arranged to define an imaging zone; an X-Raysupport base; the source and the receptor being mounted on a commonmounting member carried on the X-Ray support base and moveable relativethereto for adjusting the relative positions of the patient supporttable and the X-Ray imaging zone for imaging selected parts of thepatient; wherein the upper patient support portion is removable from thetable support base and wherein the table support base includesregistration members which allow engagement thereon only of an upperpatient support portion which is configured to match the registrationmembers so as to prevent use of an upper patient support portion whichis incompatible with the magnetic field.
 25. Apparatus for imaging of apart of a patient comprising: a patient support table, the patientsupport table comprising; a table support base for mounting in fixedposition in an imaging suite; and an upper patient support portion onwhich the patient can lie with the part of the patient exposed forimaging; the upper patient support portion being mounted for controlledmovement thereof relative to the table support base; a magneticresonance imaging system for obtaining images of the part of thepatient, the magnetic resonance imaging system comprising: a magnet foruse with a control system for controlling and varying the magneticfields, a radio frequency transmission and detection system foreliciting and detecting from the part of the patient nuclear magneticresonance signals, in response to the magnetic fields, including RFcoils arranged to be located adjacent to the part of the patient; and acomputer and display monitor for decoding and displaying an imageobtained from the detected signals; the magnet defining a coilsurrounding a horizontal axis and defining a cylindrical bore extendingbetween axial ends of the coil of the magnet with an imaging zone partway along the bore between the ends, the upper patient support portionof the patient support table being cantilevered from the table supportbase in a direction longitudinal of the axis so as to extend into thebore from one end of the magnet to the imaging zone; wherein the magnetis mounted on a magnet support arranged so that the magnet is movablebetween a magnetic resonance imaging position in which the magnet boresurrounds the patient support portion while the patient support portionremains supported on the table support base and a remote position inwhich the magnet is removed from the upper patient support portion by adistance such that the upper patient support portion is out of thestrong magnetic field of the magnet; and an X-Ray imaging systemcomprising: an X-Ray source; an X-Ray receptor; the X-Ray source and theX-Ray receptor being arranged to define an imaging zone; an X-Raysupport base; the source and the receptor being mounted on a commonmounting member carried on the X-Ray support base and moveable relativethereto for adjusting the relative positions of the patient supporttable and the X-Ray imaging zone for imaging selected parts of thepatient; wherein there is provided a safety control system forcontrolling movements of the magnet, the patient support table and theX-Ray imaging system.
 26. The apparatus according to claim 25 whereinthe safety control system is arranged to prevent forward movement of themagnet into the room in the event that the patient support table and theX-Ray imaging system are not in a park position.
 27. The apparatusaccording to claim 25 wherein the safety control system is arranged tooperate forward movement of the magnet up to a halt position spaced fromthe end of the upper patient support portion of the patient supporttable at which the magnet automatically is halted.
 28. The apparatusaccording to claim 27 wherein the patient support table is operable toadjust the upper patient support portion when the magnet is in the haltposition and wherein the patient support table is prevented fromadjusting the upper patient support portion when the magnet is movedforwardly of the halt position.
 29. The apparatus according to claim 25wherein the safety control system is arranged to operate retractionmovement of the magnet up to a halt position spaced from the end of theupper patient support portion of the patient support table at which theretraction movement automatically is halted.
 30. The apparatus accordingto claim 25 wherein the safety control system includes a status displayfor an operator which includes indication of: Enablement of movement ofthe magnet; The X-Ray imaging system and patient support table being inpark position; Enablement of movement of the X-Ray imaging system;Enablement of movement of the patient support table; The X-Ray imagingsystem being powered down to reduce RF noise during the MRI.
 31. Theapparatus according to claim 25 wherein the safety control system isarranged to power down the X-Ray imaging system to reduce RF noiseduring the MRI by removing power to all components within the room withthe exception of those necessary to maintain temperature control ofX-Ray receptors of the X-Ray imaging system.